It is customary in the construction of beds to provide a substantially smooth, flat, even mattress surface on which the sleeper lies. It is also well known that a solid board, when placed directly beneath the mattress, helps to ensure such a smooth, flat, even surface.
A problem that has been encountered even when a backboard is used beneath a mattress is that a sleeper's mass exerts a downward force on the mattress, creating a depression in the mattress, since the downward force directly beneath the recliner is greater than similar forces elsewhere on the mattress, if such forces are present at all. Such a depression is of little consequence to a single sleeper. However, where there are dual sleepers on the same mattress, disparate downward forces are exerted on the surface of the mattress thereby causing disparate depressions, which often begin to overlap. The resulting surface of the mattress creates a tendency for the sleepers to roll toward the deeper of the depressions. Because the more massive sleeper causes deeper surface depressions, the less massive sleeper will generally be drawn toward the area that the more massive sleeper occupies such that unintended contact occurs. This prevents peaceful, undisturbed sleep.
It is therefore an object of this invention to maintain two separate depressions on the same mattress so that sleepers do not have a tendency to roll toward each other as they sleep.
It is an additional object of this invention to provide for a more level sleeping surface by reinforcing the inner perimeter of the sleeping surface.
It is a further object of this invention to increase the upward support of the mattress by providing a firm underlay directly beneath it.
It is a feature of this invention that it may be easily positioned or removed depending on the number of sleepers on the mattress.